Essential oils are volatile oils derived from fruit peels and leaves, stems, flowers, bark, roots, or twigs of plants, and usually carry the odor or flavor of the plant or its fruit. Essential oils are useful as flavorings for foods and beverages, as perfumes, and for medicinal purposes. For example, essential oils include peel oils such as citrus oil. Citrus oils are derived from squeezing or pressing citrus fruit peel. Citrus oils can be derived from lemons, oranges, limes, grapefruits, tangerines, mandarins, bitter oranges, and bergamots. Other essential oils include, but are not limited to leaf oils such as mint oils, spice oils such as clove oil, and flower oils such as rose oil.
Plants and fruits from which essential oils are derived are widely cultivated, in part for the essential oils they produce. During cultivation, agricultural chemicals are often applied to the plant or fruit, or both, to control pests such as insects, fungus, and weeds. While much of the agricultural chemicals applied during cultivation are removed by washing the harvest, some agricultural chemical residue sometimes remains on the plant or fruit from which essential oils are derived and can be extracted along with the essential oils. Furthermore, agricultural chemicals such as fungicides may be applied to harvested fruit to prevent spoilage and this fruit may be subsequently processed to produce essential oil. Thus, essential oils can sometimes contain trace amounts of agricultural chemicals which are referred to herein as agricultural residue.
It is therefore desirable to remove agricultural chemical residue from essential oils and there remains a need for an effective and economical method of removing such contaminants from essential oils.